tendencies of things are noted and grouped; whilst philosophers, using the knowledge thus gained, seek to trace back the progress of events and show how this complex world has gradually been derived from a world of more and more simple composition. We are taken back in imagination even much further. We are referred to a primal haze or nebula-as the gigantic germ of a future Universe. This was the conception of Kant and of Laplace.

But whether we follow the philosopher in his bold speculations concerning the past, or listen to the biologist making his predictions as to the future stages which the germ of a given animal will pass through in the progress of its evolution-in each case the 'uniformity of nature' is tacitly assumed. This assumption underlies almost all our thoughts and actions, even in every-day life. And without such a belief regarding the succession of events science would be impossible-the very idea of it, in fact, could never have arisen. In its absence we could neither fathom the past nor illumine the future. As Mr. Mill said,*-"Were we to suppose (what it is perfectly possible to imagine) that the present order of the universe were brought to an end, and that a chaos succeeded in which there was no fixed succession of events, and the past gave no assurance of the future, if a human Syst, of Logic, 6th edit. vol. ii. p. 98.

*

being were miraculously kept alive to witness this change, he surely would soon cease to believe in any uniformity, the uniformity itself no longer existing."

It is true that in earlier times no absolute belief in the uniformity of nature existed, even amongst the select few. The Greek philosophers, including Aristotle, recognised 'chance' and 'spontaneity' as finding a definite place in Nature, and to this extent they were not sure that the future would resemble the past. But as we have become more familiar with a wider range of natural phenomena and with their mutual relations or order of appearance, so has the conception of chance or spontaneity disappeared from the scientific horizon-driven out of the field by the steady advance of Law and Order. Those who embrace the Evolution Philosophy are foremost in this opinion— they believe that no effects of whatsoever kind can occur without adequate causes, and, the conditions. being similar, that the same results will alway follow the action of any given cause. Their whole creed is, in fact, pre-eminently based upon an assumed Uniformity of Nature.

The present is essentially a time of transition in matters of opinion. Men who have been educated in one system of scientific beliefs are gradually being converted to another, because the new system is

thought to be more harmonious with the observed order of natural phenomena. This has been the case even with our chief exponents of Evolution. They have themselves had to unlearn much which they had previously learned. The doctrine of Evolution has thus been developed only by the sacrifice of many previous early beliefs and modes of thought. But it often happens that an old belief will-unknown perhaps to the person himself-leave decided traces of its previous influence, and thus prevent for a time the full realization or adoption of all the logical consequences of new views. This vestige of the old state of opinion or habit of thought is more especially apt to remain in directions where unexplained facts still exist and strong prepossessions or prejudices bar the way. Some modes of this half-unconscious inconsistency may become obvious to one worker or thinker, and some to another, according to the particular direction which his investigations or thoughts may have taken; and if they are of an important nature such inconsistencies should be pointed out from time to time. With the view, therefore, of strengthening an hypothesis which I, in common with so many other workers in science, believe to be true, I now venture to allude to certain apparent anomalies in the declared opinions of the most prominent upholders of the doctrine of Evolution in this country. It seems

all the more desirable that this should be done, since the inconsistencies may be easily shown to be wholly uncalled for, and to involve sundry unscientific conceptions. Yet the modifications of opinion which appear to be demanded-on the ground of fact as well as on the ground of reason—will necessitate very considerable and almost revolutionary changes in the accepted code of biological doctrines.

An examination of the facts of science generally and of various every-day phenomena, teaches us, according to the Evolutionist, that Matter of different kinds, situated as it is and has been, gradually tends within certain limits to become more and more complex in its internal and external constitution. Coupling this conclusion with various astronomical data, with geological data, and with facts derived from the study of the past forms of Life upon our globe, the Evolutionist essays to penetrate through the long vista of bygone ages, till he may rest his speculative gaze upon a vast rotating nebular mass of gaseous matter of comparatively simple though unknown constitution, from which he supposes our 'Universe to have been slowly evolved. Without futile questionings as to the explanation or cause of the existence of the Nebula-without speculation as to what simpler or more complex matter may have immediately preceded it—it is obvious that we may

for our own convenience direct our attention especially to any particular stage of its hypothetical existence. At the same time we must be equally free to admit that, in concentrating our attention upon the nebular stage, or upon any other, we arbitrarily break into a mysterious cycle of existence whose Cause is to us unfathomable. It is needless for my purpose, however, to attempt to concentrate the reader's attention upon a period so remote in the history of our Universe. We are led to believe that the primordial nebula as it cooled and condensed acquired a more rapid axial rotation; that masses. were gradually thrown off from its circumference; and that these in their turn condensed into rotating spheroids, which continued to circulate round the parent mass in elliptical orbits. Assuming, then, with the Evolutionist, that our own planet had a past history of this kind, we must also assume that it gradually changed from a gaseous to a fluid state before beginning to solidify by the formation of a superficial crust-a crust which gradually thickened. as the fervent heat of it and of the fluid nucleus abated by heat radiations into space. Until this stage of the Earth's history had been far advanced, no Living Things could have existed upon its surface. "Hence," as Sir William Thomson said,* "when

Inaugural Address at Meeting of British Association, Nature, Aug. 3, 1871, p. 269.